/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cassandra.config;

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import com.google.common.base.Objects;

public class ParameterizedClass
{
    public String class_name;
    public Map<String, String> parameters;

    public ParameterizedClass(String class_name, Map<String, String> parameters)
    {
        this.class_name = class_name;
        this.parameters = parameters;
        
        //我加上的
        Object v;
        Map<String, String> map = new LinkedHashMap<>();
        for (Object k : parameters.keySet()) {
            v = parameters.get(k);
            if (v != null)
                map.put(k.toString(), v.toString());
        }
        
        this.parameters = map;
    }

    @SuppressWarnings("unchecked")
    public ParameterizedClass(Map<String, ?> p)
    {
//      例如在cassandra.yaml中定义
//      seed_provider:
//          - class_name: org.apache.cassandra.locator.SimpleSeedProvider
//            parameters:
//                - seeds: "127.0.0.1"
//      p.get("parameters")是一个List，List.get(0)才是Map<String, String>
//        
//      这种方式有bug，取到的值有可能不是String类型
//      例如下面这个配置
//        commitlog_compression:
//            - class_name: LZ4Compressor
//              parameters:
//                  - chunk_length_in_kb: 64
//      就抛出
//      Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.CharSequence
//        at org.apache.cassandra.schema.CompressionParams.copyOptions(CompressionParams.java:276) ~[main/:na]
//        at org.apache.cassandra.schema.CompressionParams.createCompressor(CompressionParams.java:266) ~[main/:na]
//        at org.apache.cassandra.db.commitlog.CommitLog.<init>(CommitLog.java:103) ~[main/:na]
//        at org.apache.cassandra.db.commitlog.CommitLog.construct(CommitLog.java:84) ~[main/:na]
//        at org.apache.cassandra.db.commitlog.CommitLog.<clinit>(CommitLog.java:63) ~[main/:na]
//        ... 19 common frames omitted
        this((String)p.get("class_name"),
             p.containsKey("parameters") ? (Map<String, String>)((List<?>)p.get("parameters")).get(0) : null);
    }

    @Override
    public boolean equals(Object that)
    {
        return that instanceof ParameterizedClass && equals((ParameterizedClass) that);
    }

    public boolean equals(ParameterizedClass that)
    {
        return Objects.equal(class_name, that.class_name) && Objects.equal(parameters, that.parameters);
    }

    @Override
    public String toString()
    {
        return class_name + (parameters == null ? "" : parameters.toString());
    }
}
